/**
 * @class Ext.dom.Helper
 * @extends Ext.dom.AbstractHelper
 * @alternateClassName Ext.DomHelper
 * @alternateClassName Ext.core.DomHelper
 * @singleton
 *
 * The DomHelper class provides a layer of abstraction from DOM and transparently supports creating elements via DOM or
 * using HTML fragments. It also has the ability to create HTML fragment templates from your DOM building code.
 *
 * # DomHelper element specification object
 *
 * A specification object is used when creating elements. Attributes of this object are assumed to be element
 * attributes, except for 4 special attributes:
 *
 * - **tag** - The tag name of the element.
 * - **children** or **cn** - An array of the same kind of element definition objects to be created and appended.
 *   These can be nested as deep as you want.
 * - **cls** - The class attribute of the element. This will end up being either the "class" attribute on a HTML
 *   fragment or className for a DOM node, depending on whether DomHelper is using fragments or DOM.
 * - **html** - The innerHTML for the element.
 *
 * **NOTE:** For other arbitrary attributes, the value will currently **not** be automatically HTML-escaped prior to
 * building the element's HTML string. This means that if your attribute value contains special characters that would
 * not normally be allowed in a double-quoted attribute value, you **must** manually HTML-encode it beforehand (see
 * {@link Ext.String#htmlEncode}) or risk malformed HTML being created. This behavior may change in a future release.
 *
 * # Insertion methods
 *
 * Commonly used insertion methods:
 *
 * - **{@link #append}**
 * - **{@link #insertBefore}**
 * - **{@link #insertAfter}**
 * - **{@link #overwrite}**
 * - **{@link #createTemplate}**
 * - **{@link #insertHtml}**
 *
 * # Example
 *
 * This is an example, where an unordered list with 3 children items is appended to an existing element with
 * id 'my-div':
 *
 *     var dh = Ext.DomHelper; // create shorthand alias
 *     // specification object
 *     var spec = {
 *         id: 'my-ul',
 *         tag: 'ul',
 *         cls: 'my-list',
 *         // append children after creating
 *         children: [     // may also specify 'cn' instead of 'children'
 *             {tag: 'li', id: 'item0', html: 'List Item 0'},
 *             {tag: 'li', id: 'item1', html: 'List Item 1'},
 *             {tag: 'li', id: 'item2', html: 'List Item 2'}
 *         ]
 *     };
 *     var list = dh.append(
 *         'my-div', // the context element 'my-div' can either be the id or the actual node
 *         spec      // the specification object
 *     );
 *
 * Element creation specification parameters in this class may also be passed as an Array of specification objects. This
 * can be used to insert multiple sibling nodes into an existing container very efficiently. For example, to add more
 * list items to the example above:
 *
 *     dh.append('my-ul', [
 *         {tag: 'li', id: 'item3', html: 'List Item 3'},
 *         {tag: 'li', id: 'item4', html: 'List Item 4'}
 *     ]);
 *
 * # Templating
 *
 * The real power is in the built-in templating. Instead of creating or appending any elements, {@link #createTemplate}
 * returns a Template object which can be used over and over to insert new elements. Revisiting the example above, we
 * could utilize templating this time:
 *
 *     // create the node
 *     var list = dh.append('my-div', {tag: 'ul', cls: 'my-list'});
 *     // get template
 *     var tpl = dh.createTemplate({tag: 'li', id: 'item{0}', html: 'List Item {0}'});
 *
 *     for(var i = 0; i < 5, i++){
 *         tpl.append(list, [i]); // use template to append to the actual node
 *     }
 *
 * An example using a template:
 *
 *     var html = '<a id="{0}" href="{1}" class="nav">{2}</a>';
 *
 *     var tpl = new Ext.DomHelper.createTemplate(html);
 *     tpl.append('blog-roll', ['link1', 'http://www.edspencer.net/', "Ed's Site"]);
 *     tpl.append('blog-roll', ['link2', 'http://www.dustindiaz.com/', "Dustin's Site"]);
 *
 * The same example using named parameters:
 *
 *     var html = '<a id="{id}" href="{url}" class="nav">{text}</a>';
 *
 *     var tpl = new Ext.DomHelper.createTemplate(html);
 *     tpl.append('blog-roll', {
 *         id: 'link1',
 *         url: 'http://www.edspencer.net/',
 *         text: "Ed's Site"
 *     });
 *     tpl.append('blog-roll', {
 *         id: 'link2',
 *         url: 'http://www.dustindiaz.com/',
 *         text: "Dustin's Site"
 *     });
 *
 * # Compiling Templates
 *
 * Templates are applied using regular expressions. The performance is great, but if you are adding a bunch of DOM
 * elements using the same template, you can increase performance even further by {@link Ext.Template#compile
 * "compiling"} the template. The way "{@link Ext.Template#compile compile()}" works is the template is parsed and
 * broken up at the different variable points and a dynamic function is created and eval'ed. The generated function
 * performs string concatenation of these parts and the passed variables instead of using regular expressions.
 *
 *     var html = '<a id="{id}" href="{url}" class="nav">{text}</a>';
 *
 *     var tpl = new Ext.DomHelper.createTemplate(html);
 *     tpl.compile();
 *
 *     //... use template like normal
 *
 * # Performance Boost
 *
 * DomHelper will transparently create HTML fragments when it can. Using HTML fragments instead of DOM can significantly
 * boost performance.
 *
 * Element creation specification parameters may also be strings. If {@link #useDom} is false, then the string is used
 * as innerHTML. If {@link #useDom} is true, a string specification results in the creation of a text node. Usage:
 *
 *     Ext.DomHelper.useDom = true; // force it to use DOM; reduces performance
 *
 */
(function() {

// kill repeat to save bytes
var afterbegin = 'afterbegin',
    afterend = 'afterend',
    beforebegin = 'beforebegin',
    beforeend = 'beforeend',
    ts = '<table>',
    te = '</table>',
    tbs = ts+'<tbody>',
    tbe = '</tbody>'+te,
    trs = tbs + '<tr>',
    tre = '</tr>'+tbe;

Ext.define('Ext.dom.Helper', {
    extend: 'Ext.dom.AbstractHelper',

    tempTableEl: null,

    tableRe: /^table|tbody|tr|td$/i,

    tableElRe: /td|tr|tbody/i,

    /**
     * @property {Boolean} useDom
     * True to force the use of DOM instead of html fragments.
     */
    useDom : false,

    /**
     * Creates new DOM element(s) without inserting them to the document.
     * @param {Object/String} o The DOM object spec (and children) or raw HTML blob
     * @return {HTMLElement} The new uninserted node
     */
    createDom: function(o, parentNode){
        var el,
            doc = document,
            useSet,
            attr,
            val,
            cn;

        if (Ext.isArray(o)) {                       // Allow Arrays of siblings to be inserted
            el = doc.createDocumentFragment(); // in one shot using a DocumentFragment
            for (var i = 0, l = o.length; i < l; i++) {
                this.createDom(o[i], el);
            }
        } else if (typeof o == 'string') {         // Allow a string as a child spec.
            el = doc.createTextNode(o);
        } else {
            el = doc.createElement(o.tag || 'div');
            useSet = !!el.setAttribute; // In IE some elements don't have setAttribute
            for (attr in o) {
                if (!this.confRe.test(attr)) {
                    val = o[attr];
                    if (attr == 'cls') {
                        el.className = val;
                    } else {
                        if (useSet) {
                            el.setAttribute(attr, val);
                        } else {
                            el[attr] = val;
                        }
                    }
                }
            }
            Ext.DomHelper.applyStyles(el, o.style);

            if ((cn = o.children || o.cn)) {
                this.createDom(cn, el);
            } else if (o.html) {
                el.innerHTML = o.html;
            }
        }
        if (parentNode) {
            parentNode.appendChild(el);
        }
        return el;
    },

    ieTable: function(depth, s, h, e){
        this.tempTableEl.innerHTML = [s, h, e].join('');

        var i = -1,
            el = this.tempTableEl,
            ns;

        while (++i < depth) {
            el = el.firstChild;
        }
        // If the result is multiple siblings, then encapsulate them into one fragment.
        ns = el.nextSibling;

        if (ns) {
            var df = document.createDocumentFragment();
            while (el) {
                ns = el.nextSibling;
                df.appendChild(el);
                el = ns;
            }
            el = df;
        }

        return el;
    },


    /**
     * @ignore
     * Nasty code for IE's broken table implementation
     */
    insertIntoTable: function(tag, where, el, html) {
        var node,
            before;

        this.tempTableEl = this.tempTableEl || document.createElement('div');

        if (tag == 'td' && (where == afterbegin || where == beforeend) ||
                !this.tableElRe.test(tag) && (where == beforebegin || where == afterend)) {
            return null;
        }
        before = where == beforebegin ? el :
                where == afterend ? el.nextSibling :
                        where == afterbegin ? el.firstChild : null;

        if (where == beforebegin || where == afterend) {
            el = el.parentNode;
        }

        if (tag == 'td' || (tag == 'tr' && (where == beforeend || where == afterbegin))) {
            node = this.ieTable(4, trs, html, tre);
        } else if ((tag == 'tbody' && (where == beforeend || where == afterbegin)) ||
                (tag == 'tr' && (where == beforebegin || where == afterend))) {
            node = this.ieTable(3, tbs, html, tbe);
        } else {
            node = this.ieTable(2, ts, html, te);
        }
        el.insertBefore(node, before);
        return node;
    },

    /**
     * @ignore
     * Fix for IE9 createContextualFragment missing method
     */
    createContextualFragment: function(html){
        var div = document.createElement("div"),
            fragment = document.createDocumentFragment(),
            i = 0,
            length, childNodes;

        div.innerHTML = html;
        childNodes = div.childNodes;
        length = childNodes.length;

        for (; i < length; i++) {
            fragment.appendChild(childNodes[i].cloneNode(true));
        }

        return fragment;
    },

    applyStyles: function(el, styles) {
        if (styles) {
            el = Ext.fly(el);
            if (typeof styles == "function") {
                styles = styles.call();
            }
            if (typeof styles == "string") {
                styles = Ext.dom.Element.parseStyles(styles);
            }
            if (typeof styles == "object") {
                el.setStyle(styles);
            }
        }
    },

    /**
     * Alias for {@link #markup}.
     * @inheritdoc Ext.dom.AbstractHelper#markup
     */
    createHtml: function(spec) {
        return this.markup(spec);
    },

    doInsert: function(el, o, returnElement, pos, sibling, append) {
        
        el = el.dom || Ext.getDom(el);

        var newNode;

        if (this.useDom) {
            newNode = this.createDom(o, null);

            if (append) {
                el.appendChild(newNode);
            }
            else {
                (sibling == 'firstChild' ? el : el.parentNode).insertBefore(newNode, el[sibling] || el);
            }

        } else {
            newNode = this.insertHtml(pos, el, this.markup(o));
        }
        return returnElement ? Ext.get(newNode, true) : newNode;
    },

    insertHtml: function(where, el, html) {
        var hash = {},
            hashVal,
            range,
            rangeEl,
            setStart,
            frag,
            rs;

        where = where.toLowerCase();
        // add these here because they are used in both branches of the condition.
        hash[beforebegin] = ['BeforeBegin', 'previousSibling'];
        hash[afterend] = ['AfterEnd', 'nextSibling'];

        // if IE and context element is an HTMLElement
        if (el.insertAdjacentHTML) {
            if (this.tableRe.test(el.tagName) && (rs = this.insertIntoTable(el.tagName.toLowerCase(), where, el, html))) {
                return rs;
            }

            // add these two to the hash.
            hash[afterbegin] = ['AfterBegin', 'firstChild'];
            hash[beforeend] = ['BeforeEnd', 'lastChild'];
            if ((hashVal = hash[where])) {
                el.insertAdjacentHTML(hashVal[0], html);
                return el[hashVal[1]];
            }
            // if (not IE and context element is an HTMLElement) or TextNode
        } else {
            // we cannot insert anything inside a textnode so...
            if (Ext.isTextNode(el)) {
                where = where === 'afterbegin' ? 'beforebegin' : where;
                where = where === 'beforeend' ? 'afterend' : where;
            }
            range = Ext.supports.CreateContextualFragment ? el.ownerDocument.createRange() : undefined;
            setStart = 'setStart' + (this.endRe.test(where) ? 'After' : 'Before');
            if (hash[where]) {
                if (range) {
                    range[setStart](el);
                    frag = range.createContextualFragment(html);
                } else {
                    frag = this.createContextualFragment(html);
                }
                el.parentNode.insertBefore(frag, where == beforebegin ? el : el.nextSibling);
                return el[(where == beforebegin ? 'previous' : 'next') + 'Sibling'];
            } else {
                rangeEl = (where == afterbegin ? 'first' : 'last') + 'Child';
                if (el.firstChild) {
                    if (range) {
                        range[setStart](el[rangeEl]);
                        frag = range.createContextualFragment(html);
                    } else {
                        frag = this.createContextualFragment(html);
                    }

                    if (where == afterbegin) {
                        el.insertBefore(frag, el.firstChild);
                    } else {
                        el.appendChild(frag);
                    }
                } else {
                    el.innerHTML = html;
                }
                return el[rangeEl];
            }
        }
        //<debug>
        Ext.Error.raise({
            sourceClass: 'Ext.DomHelper',
            sourceMethod: 'insertHtml',
            htmlToInsert: html,
            targetElement: el,
            msg: 'Illegal insertion point reached: "' + where + '"'
        });
        //</debug>
    },

    /**
     * Creates a new Ext.Template from the DOM object spec.
     * @param {Object} o The DOM object spec (and children)
     * @return {Ext.Template} The new template
     */
    createTemplate: function(o) {
        var html = this.markup(o);
        return new Ext.Template(html);
    }

}, function() {
    Ext.ns('Ext.core');
    Ext.DomHelper = Ext.core.DomHelper = new this;
});


})();
